hBMP-2 gene modified tissue-engineered bone used for perio-implant bone defect

Objective: To study the effect of hBMP-2 gene modified tissue-engineered bone used for bone defect of dental implant. Methods: Rabbit periosteal-derived osteoblasts(POBs)were cultured and transfected with adenoviral vectors encoding hBMP-2 gene in vitro, and the multiplicity of infection were 100. After the transfected osteoblasts or the control ones were concentrated to 5×107cells/ml, they were combined with Bio-oss to construct tissue-engineered bone. Eighteen New Zealand white rabbits were randomly divided into 3 groups and a BLB fixture was implanted in each side of mandible of every animal. Some of the buccal side bone was removed and an opening bone defect was made that 1/3 of the implant was exposed. The defects were repaired with 3 meterials respecetively which were (1) hBMP-2 gene modified tissue-engineered bone,(2) tissue-engineered bone and (3)Bio-oss(control group). At 1 month and 3 months postoperatively, specimens were obtained, X-ray, histomorphology and immunohistochemical staining were performed and the bone ingrowth fraction (BIF) and the osseointegration index (OI) were observed by quantitative histology. One-way ANOVA and multiple comparisons were used to determine if there were statistical differences between the groups. Results: All 36 dental implants healed without any complications, no one became loose or broken off and X-ray images showed no blocking shadow between dental implants and bone tissue. At both time postoperatively, the BIF and the OI of group 1 were significantly higher than those of group 2(P<0.05), and the BIF and the OI of group 2 were higher than those of group 3(P<0.05). Immunolabelling for hBMP-2 was positive in group 1 one month postoperatively. Conclusions: hBMP-2 gene modified tissue-engineered bone was a more ideal material in the reconstruction of perio-implant bone defect.